Location　privacy　protection　method　of　Location-based　Services　(LBS)　system　mostly　depends　on　the　trusted　third　party　anonymity　server.　When　the　attacker　has　sufficient　background　knowledge,　it　is　proved　that　Location　privacy　can＇t　be　adequately　protected　by　k-anonymity　based　on　location　obfuscation　enforced　using　cloaking　regions.　But　perturbation-based　mechanisms　with　differential　privacy　have　been　proven　effective　to　defend　attackers　with　any　background　knowledge.　In　this　paper,　k-anonymity　and　differential　privacy　are　used　to　generate　a　perturbation,　according　to　that　the　incremental　nearest　neighbor　query　is　enforced,　so　as　to　achieve　the　purpose　of　LBS　privacy　protection.　Experiments　are　presented　to　demonstrate　how　perturbation-based　mechanisms　provide　a　well-balanced　tradeoff　between　privacy　and　service　accuracy.